Machine for producing a longitudinally folded stack of webs



Sept. 17, 1968 R. H. FRICK Y 3,401,928

MACHINE FOR PRODUCING A LONGITUDINALLY FOLDED STACK OF WEBS Filed Aug.19, 1966 s Sheecs-Sheet 1 Sept. 17, 1968 R. H. FRI-CK 3,401,928

MACHINE FOR PRODUCING A LONGITUDINALLY FOLDED STACK OF WEBS Filed Aug.19, 1966 3 Sheets-Sheet 2 R. H. FRICK Sept. 17, 1968 MACHINE FORPRODUCING A LONGITUDINALLY FOLDED STACK OF WEBS 3 Sheets-Sheet 5 mm R-rFiled Aug. 19, 1966 United States Patent 3,401,928 MACHINE FOR PRODUCINGA LON GITUDINALLY FOLDED STACK 0F WEBS Richard H. Frick, Neenah, Wis.,assignor to Kimberly- Clark Corporation, Neenah, Wis., a corporation ofDelaware Filed Aug. 19, 1966, Ser. No. 573,585 Claims. (Cl. 270-40)ABSTRACT OF THE DISCLOSURE A machine for folding uniform width webs ofsheet material into a stack with each Web being folded to have twoquarter folds on the top surface and a half width fold on the bottom,the machine comprising a series of folding devices each of whichoverfolds the top quarter width fold and underfolds the bottom halfwidth fold with respect to the intermediate quarter width fold and eachfolding device having first, second and third folding edges disposed ina single plane and joining at a single point, a fourth folding edgeextending from said point at obtuse angles to said first and secondfolding edges so that the central zone of the web may be passed over thefirst folding edge while a lateral edge strip of the web passessuccessively over the fourth, second and third folding edges to befolded underneath the central zone of the web, each said folding devicealso including a fifth folding edge extending from a second point onsaid first folding edge spaced from said first point and extendingobliquely with respect to said first folding edge and being disposed inthe same plane as said fourth folding edge and a sixth folding edgesubstantially in said first named plane and extending from said secondpoint to said second folding edge so that a lateral edge strip of theweb may successively pass over said fifth and sixth folding edges to befolded over said central zone of the Web.

My invention relates to papermaking machines and paper products and moreparticularly to folded webs of paper or other sheet material and tomachines for folding the webs.

Herbert H. Scholz and I have proposed in co-pending application, Ser.No. 567,440, filed July 25, 1966, a change or modification of thelongitudinal web interfolding structures disclosed in Greiner et al.Patent 3,066,932, issued Dec. 4, 1962. In brief, this modification ofthe Greiner et al. structures essentially was the substitution of amodified type of folding device or board for one of the series offolding devices or boards disclosed in the Greiner et al. patent. Themodified type of folding device was of such construction that it notonly allowed the device to be used for interfolding a web passing overthe device with a previously folded stack of webs, but the modifiedfolding device also, on a re-threading, was capable of folding the webpassing over the device back upon itself along the longitudinal centerline of the previously interfolded stack of webs.

It is an object of the present invention to utilize a plurality of suchmodified folding devices or boards positioned in tandem and in a seriesso that the series of devices is not only capable of longitudinallyinterfolding a series of webs, similar to the interfolding action of thefolding devices disclosed in the Greiner et al. patent, but is alsocapable of laying down a series of webs having the top halves foldedback upon themselves along longitudinal center lines, without anyinterfolding between the webs, so as to form a Z-fold type of foldedstack of webs.

The invention consists of the novel constructions, arrangements anddevices to be hereinafter described and 3,401,928 Patented Sept. 17,1968 claimed, for carrying out the above stated objects, and such otherobjects, as will be apparent from the following description of apreferred form of the invention, illustrated with reference to theaccompanying drawings, wherein:

FIG. 1 is a partial plan view of a folding mechanism incorporating theprinciples of the invention and including a plurality of folding boardsdisposed in a series;

FIG. 2 is a view taken substantially on line 22 of FIG. 1 and showing anend perspective view of one of the folding boards of the invention;

FIG. 3 is a view similar to FIG. 2 but with the folding board being usedin a different way;

FIG. 4 is a side elevational view of the folding board illustrated inFIGS. 2 and 3;

FIG. 5 is a view taken substantially on line 5-5 of FIG. 1 and showingan end perspective view of another folding board of the foldingmechanism;

FIG. 6 is a view similar to FIG. 5 but with the folding board being usedin a different manner;

FIG. 7 is a sectional view taben substantially on line 77 of FIG. 1 andshowing a stack of paper Webs that have been folded utilizing thefolding mechanism illustrated in the previous figures;

FIGS. 8 and 9 are views similar to that of FIG. 7 but with the foldingboards being threaded differently to fold the webs differently;

FIG. 10 is a perspective view of a carton of C-folded tissuesconstituting prior art;

FIG. 11 is a perspective view of tissues as folded in FIG. 8 anddisposed in a carton; and

FIG. 12 is a diagrammatic illustration of one of the folding boardssetting forth various dimensions and angles of the board.

Like characters of reference designate like parts in the several views.

Referring to FIG. 1 in particular, the folding mechanism of theinvention may be seen to utilize two types A and B of folding boards ordevices... The two types of folding boards A and B are alternatelyarranged in a series, with each type B device following a type A deviceand being arranged betwen two type A devices except for the last type Bdevice in the series.

As seen in FIG. 1, the particular folding device B follows theparticular device A the device A which is identical to the first deviceA follows the device B and the device B which is identical to the deviceB follows the device A Likewise, in the series of folding devices B B Betc. (not shown), identical with device B will respectively followdevices A A A etc. (not shown), identical with device A Referring toFIG. 2 showing the device A each type A device comprises fiat sheetmetal portions 10, 11 and 12 which are preferably made of a single pieceof sheet material folded along lines 13 and 14. The portion 12 may beconsidered as a base portion preferably used ina horizontal position;and, as will be observed from FIG. 4, the portion 10 extends upwardlyand at an obtuse angle with respect to the portion 12. The line 14, aswill hereafter appear, extends parallel with the path X of movement of aweb or webs passing over the folding board and parallel with the edgesof the webs. The portion 12 terminates in an edge 15 which extends at anacute angle with respect to the line 14, the apex of the lines 14 and 15being at a point 16; and the line 13, as well as the lower edge 17 ofthe portion 10, terminate at the point 16. The Greiner et al. Patent3,066,932 may be referred to for the preferred relationship of the fiatportions 10, 11 and 12 and the lines defining the edges of theseportions with respect to each other, in order that a web may pass overthe device and be folded by it without wrinkling or stretching ofportions of the web.

The flat portion 12 is preferably provided witha side extension 12a atone end of the board by means of which the portion 12 may be supportedfrom a table 18 (see FIG. 4), and the flat portion is provided with anextension 100 by means of which the other end of the board may besupported. An upstanding stud 19 may be provided for supporting theportion 12, the stud extending through the extension 12a and a pluralityof nuts 20 being provided on the stud above and below the portion 12a.The other end of the board may be supported by means of a standard 21fixed on the table 18 with the portion 10a being fixed to a collar 22that in turn is fixed on the standard 21.

The portion 10 is provided with a lip-like extension 23 meeting with theportion 10 along the line 17. A slot 24 is provided in the portions 10and 23, and a rod 25 is fixed at one end to the lip portion 23 andterminates substantially above the line 14.

The dispositions of the slot 24 and of the bar 25 are preferably thoseset forth in the co-pending application of Richard H. Frick and HerbertC. Scholz, Ser. No. 567,440, hereinabove referred to, in order that aweb passing through the slot 24 and over the bar 25 will not bewrinkled, and these relationships are briefly the following:

Cos L-One fl W T811 W Tan The angle M denotes the angle at which theslot 24 is disposed with respect to a vertical line 26 that extendsupwardly on the flat portion 10 from a point 27, which is thesubstantial point of intersection of the slot 24 and the inner orfolding edge 25a of the bar 25. Assuming that the portion 12 ishorizontal, the line 26 lies in a vertical plane which also includes aline 28 that is a longitudinal center line of a stack of interfoldedwebs, with the plane being parallel with the direction of movement X ofthe folded webs. The side edge of the stack of folded webs, as willhereinafter appear, is substantially along the line 14, and a line 29 isan imaginary line in the flat portion 10 extending upwardly and in thesame vertical plane as the line 14. The lines 26 and 29 are, of course,parallel, and the same is true for the lines 14 and 28. The angle N isthe angle between the bar 25 and the line 14 which is parallel with thedirection of web travel X. The angle L is the angle at which the portion10 extends with respect to the portion 12. The quantity W is equal tothe width of the web portion which is folded over by the bar 25-thequantity W may, for example, in the case to be hereinafter described, beequal to One-half the width of the interfolded stack of webs orone-fourth the width of a web prior to any folding. The distance f isthe distance from the line 17 to a line 30, which is the distance W inlength and which intersects with both the lines 24 and 29 and isparallel to the line 17. The distance e is the component of the distancef along the path X and l is the distance from the line 17 to theintersection of the bar .25 and the line 14.

A paper web p from a roll 31 of paper web is supplied to the firstfolding device A (see FIG. 1). A guide bar 32 receives the web p fromthe roll 31; and the bar 32 is suitably mounted with respect to thetable 18, at a degree angle with respect to the direction X at which thewebs pass under the folding devices on the table 18. The standard 21 forthe device A is provided with a guide roll 33 at its upper end, and theweb 2 passes from the guide bar 32 onto the roll 33 and from thence ontothe lower face of the fiat portion 10 of the first folding device A Allof the type A folding devices in the folding mechanism are identical. Atype B folding device is a reverse image of a type A folding device asabove described, and the first folding device B in the series is shownin FIGS. 5 and 6. Each of the devices B basically is made up of planesheet metal portions 10, 11' and 12, slots 24' and rods 25', and theseparts are in the same dispositions with respect to each other as havebeen previously mentioned with respect to corresponding parts in a typeA device. The first type B folding device B is supplied with a web qfrom a roll 31 which passes over a guide bar 32 to a roll 33, and theseparts correspond with the similarly numbered parts described above inconnection with the first folding device A The subsequent foldingdevices A and B illustrated in FIG. 1 are similarly supplied with webs rand s respectively, and still additional folding devices in the series(not illustrated) are similarly supplied with webs t, u, v, w, x, y and2 (not shown in FIG. 1).

The series of type A and type B folding devices alternately arranged, asillustrated in FIG. 1, may be utilized for producing an interfolded webas illustrated in FIG. 7. In this case, the folding devices functionsubstantially the same as the two types of folding devices described inthe above mentioned patent to Greiner et al., No. 3,066,932; and, inthis case, the slots 24 and 24' and the rods 25 and 25' of the foldingdevices are not used.

For such interfolding, the webs (q to z) passing onto their respectivefolding boards each has a longitudinal one-half of it passing down thelower surface of the plane portion 10 or 10' and under the lip 23 or 23into a path of movement of the folded stack of webs in the direction Xalong the upper surface of the table 18. The other longitudinal halvesof the webs pass under the plane portions 10 or 10', under the planeportions 11 or 11, under the plane portions 12 or 12' and around thefolding edges 15 or 15 so that these halves of the Webs are foldedunderneath the first longitudinal halves of the Webs. If the particular'board under consideration is one of the boards subsequent to the firstboard A the second longitudinal one-half of the web being folded underthe first longitudinal one-half is at the same time also insertedunderneath the uppermost fold of the stack of webs folded by previousfolding boards.

The operation of the folding board B is particularly shown in FIG. 5,and it will be observed that the left half of the web q, as the device Bis illustrated in this figure, passes downwardly underneath the planeportion 10 and under the lip 23 to move in the path of travel of theinterfolded webs indicated by the arrow X. The right half of the web qpasses downwardly on the lower surface of the plane portion 10', aroundthe bend line 13, on the undersurface of the plane portion 11', aroundthe bend line 14', on the undersurface of the plane portion 12' and fromthence around the edge 15' of the portion 12 to thereby underfold thishalf of the web underneath the first half of the web that passesunderneath the lip 23'. The half of the web passing underneath the lip23 is indicated by the web fold q in FIGS. 2 and 5, and the half of theweb underfolded by passing around the portions 10, 11' and 12' isindicated by the web fold q in these figures.

The web p has been folded by the previous board A and the upper fold pof this web has been trained to pass over and to lie in contact with theupper surface of the plane portion 12' of the board B so that as thelower fold q is folded by the folding edge 15' underneath the top fold qthe fold q is at the same time positioned under- .neath the top fold pof the previous web p. Thus, the Web q has been longitudinallyinterfolded by the folding board B; with the previously folded web p.

The subsequent folding device A functions substantially in the samemanner except that it folds a web from the other side of the stack, andthe similar operation of the board A is illustrated in FIG. 2. As seenin this figure, the right half of the web 1' passes underneath theportion 10 and the lip 23 into the path X so as to become the web fold rThe left half of the web r passes underneath the portions 10, 11 and 12and from thence around the folding edge 15 so as to be folded underneaththe web fold r to thereby become the web fold r The web fold 11 of theinterfolded stack of webs leaving the folding device B is trained topass over the horizontal plane portion 12, and the web fold r is therebynot only folded under the web fold r but is also at the same time foldedunder the web fold q on the top of the previously folded stack of websso as to complete the interfolding.

The first folding device A functions in exactly the same manner as thefolding device A except that, inasmuch as the folding board A is thefirst of the series of boards, there are no previously interfolded webs;and the folding board A thus simply has the effect of folding the fold punder the fold p;,,.

The subsequent type A boards function in the same manner as the type Aboards just described, and the subsequent type B boards function in thesame manner as the board B All of the folding boards, subsequent to thefirst board A function similarly to underfold a longitudinal half of theweb passing over the board as well as to fold a longitudinal half ofthis web underneath the uppermost fold of the previously interfoldedstack of webs. It will be understood that, for setting up the foldingmechanism, each of the individual webs is threaded over its respectivefolding board A B A B etc., and the resultant webs are interfolded byhand in the movement path X; and, in order to set the machine inoperation, the webs in their interfolded condition are simply drawnalong in the path X by any suitable web pulling mechanism (not shown) sothat individual webs are drawn over their individual folding boards andalong the path X.

The boards A B A B etc., function with respect to webs p, q, r, s and t,in order to produce the interfolded stack of webs which is shown in FIG.7. Referring to FIG. 7, it will be observed that the web fold q liesbetween the web folds p and 11 the web folds 1' and p lie between theweb folds q and g the web folds q; and s lie between the web folds r andr the web folds 1' and t lie between the web folds s and s and the webfold s lies between the web folds t and t so that the stack of webs iseffectively interfolded. Thus, if the elongate stack of folded webs iscut into segments, the top fold t of the stack may be grasped; and inpulling and in removing the cut segment of the web t from the stack, thefold A; will at the same time be pulled upwardly; and, assuming that thesegment of interfolded webs is in a carton with a dispensing window inits top panel, the top fold s will be partially pulled through thewindow for subsequent removal. This particular arrangement ofinterfolded webs is particularly suitable if the webs are of crepedtissue suitable for facial usage, and the tissues may thus be removedone at a time from the enclosing carton, and each tissue will pull afold of the succeeding tissue into view for ready subsequent usage.Although only the five webs p, q, r, s and t have been illustrated inFIG. 7, it will be obvious that the succeeding folding boards in theseries will produce subsequent folded webs which are interfolded withthemselves and with previously folded webs in the same manner and withthe same pattern as is illustrated with respect to the webs p to t inFIG. 7.

In the event that it is desired to produce a non-interfolded stack ofwebs, the slots 24 and 24 and the folding rods 25 and 25' may beutilized. In this case, each of the folding devices is threaded in aslightly different manner with the particular web folded by the device.

Referring to FIG. 3 illustrating the folding device A it will beobserved that the right fourth of the web r is directed through the slot24 and over the folding bar 25 instead of passing underneath the lip 23with the rest of the right half width of web r. The distance from thepoint 16 to the end of the slot 24 at point 27, in the particular formof the folding device illustrated, is equal to one-fourth the width ofthe complete web r, and the right one-fourth of the web r as it passesthrough the slot 24 and over the folding rod 25 is folded over the otherone-fourth of the web which would otherwise constitute a part of the webfold r if the board A were used as first described. Thus, as isillustrated in FIG. 3, with the slot 24 and the rod 25 being utilized;the folding device A folds the half web fold or width r underneath; aquarter fold r passes underneath the lip 23 so as to remain on top ofthe web fold 1' and a quarter width web fold r is folded on top of thequarter width web fold r None of the previously folded webs, utilizingthe boards in this manner, passes over the plane portion 12; and,therefore, there is no interfolding. The web p is folded by the firsttype A board in the same manner as the web r is folded by the board Aand the web p appears as shown in FIG. 3; with a bottom half width foldp and upper quarter folds p and 17 The board B functioning in the samemanner as do the type A boards as just described, has the leftonequarter of the web q passing through its slot 24 and over its foldingbar 25 (see FIG. 6). The board B folds in the same manner as the boardsA and A but in the opposite direction so that the board B produces alower one-half width web fold q, and upper one-quarter width folds q andq.,,.

The boards as used in this manner do not interfold, and the stackproduced by the boards operating in this manner is illustrated in FIG.8. All of the webs are folded in the same manner so that each has two,one-fourth width, folds located above a full one-half width fold. Thisfolding may be termed a modified Z-fold, and the webs simply lie one onanother. Due to the fact that the type A boards and type B boards foldin opposite directions, the one-fourth width folds lie on opposite sidesof the stack and the crease or f-old between the quarter width foldslies substantially on the longitudinal center line of the stack offolded webs. If the webs p, q, r, s and t are of facial quality tissuecut into segments and packaged in cartons with openings in the toppanels, the segments of the individual webs may be withdrawn through thetop openings individually without disturbance of the webs locatedunderneath, since the boards used in this manner do not interfold thewebs. In particular, referring to FIG. 8, it will be observed that theweb p, with its half fold p and its quarter folds p and p is located inthe stack completely beneath all parts of the web q. Likewise, the webq, with its half fold q and its quarter folds (1 and 11 is located belowall parts of the succeeding webs r, s and t. Also, it will be observedthat the quarter folds p and p extend from the left side of the stacksubstantially to the longitudinal center of the stack while the quarterfolds q and (1 of the web q also extend substantially to thelongitudinal center of the stack, but from the right hand side of thestack. The other webs alternate from opposite sides of the stack asillustrated. Since the quarter folds of the individual webs extend tothe longitudinal center of the stack, the crease between the quarterfolds of the uppermost web segment may be easily grasped by a personthrusting his hand through the tissue withdrawal opening in the toppanel of a carton in which segments of the folded webs are packaged, sothat the uppermost web can be easily grasped and withdrawn from thecarton.

It is also possible using the modified Z-fold and using the type A andtype B boards in the manner just described, to interfold the paper webs,and the webs as so interfolded are illustrated in FIG. 9. In this case,each of the boards after the first board A has the lowermost one-fourthfold of the previously folded web trained on and traveling over thehorizontal plane portion 12 or 12' of the board, so that the half foldof the web folded by the particular board is inserted between the halffold and the lowermost quarter fold of the previously folded web.

As previously described in connection with FIG. 6, the folding board Bhas the effect of folding the half width fold q, under the fold q;; andfolding the: quarter width fold up, over the fold q If the fold p of thepreviously folded web is made to travel on and pass over the uppersurface of the plane portion 12' of the board B the fold q is insertedbetween the folds p and 17 as shown in FIG. 9. The operation of theboard A in utilizing the slot 24 and rod 25 is illustrated in FIG. 3;and, as previously described, the board operating in this mannerunderfolds the one-half width fold r under the one-fourth width fold 1'and overfolds the one-fourth width fold r over the one-quarter widthfold r If the fold (1 from the previously folded web is made to passalong and over the upper surface of the plane portion 12 of the board Athe fold r is positioned between the folds q and g as shown in FIG. 9.The first folding board A functions in the same manner as the board Abut there is no previously folded web traveling under the board A intowhich its lower one-half width fold p may be positioned.

The subsequent type A boards and the subsequent type B boards functionin the same manner as just described in connection with the board A andthe board B to fold the lowermost one-half width fold produced by theparticular board in between the one-half width and lowermost one-fourthwidth folds produced by the previous folding board, and thus the type ofinterfolding in FIG. 9 is produced by the boards operating in thismanner. With this type of interfolding, it will be observed that theonequarter width folds of any particular web having the subscripts 3 and4 are positioned bet-ween the one-half width folds of the subsequent twowebs. For example, the folds p and p from the web p passing over thefolding board A are located between the one-half width folds q and r ofthe subsequent two webs q and r. As will be observed, on the top of thestack as shown in FIG. 9, there are four folds present, namely the foldsZ3, Z4, 31/ and y; Each of these folds is one-fourth width and thereforethe fold lines between these folds lie along the longitudinal center ofthe stack. Therefore, assuming that a segment of the stack asillustrated in FIG. 9 is positioned in a cartoon with a windowed toppanel, the users hand may be reached into the carton through the windowand either of the webs z or y may be grasped in order to remove a websegment from the carton. Since the webs are interfolder, a withdrawal ofone web from the carton acts to pull a lower web partially through thewindow of the carton so as to make it available. In order to increasethe adherence of one web with respect to the other to promote thisaction, the tissue webs as so folder may be compressed, such as forexample, as is described in Patents 3,172,563, issued to kenneth J.Harwood on Mar. 9, 1965, and 3,172,564 issued to Kenneth M. Enloe andLeRoy L. Peterson on Mar. 9, 1965; and such compression also has theeffect, as described in these patents, of allowing the webs to be packedin cartons of less height than would otherwise be possible.

Referring to FIG. 8, it will be observed that the modified Z-foldedwebs, without interfolding, provide an edge on the top of the stackalong the longitudinal center line of the stack, which is a folded edgerather than a cut edge. With this arrangement, there is no oppositeedge, cut or otherwise, on the top surface of the stack; and a personmay easily grasp the folded edge on the top of a cut segment of the webstack for the purpose of removing the top web out of a carton, forexample, for the cut segment.

In addition, it will be noted that since the folded edge on the top ofthe stack extends to the longitudinal center line of the stack, thestack may be exactly one-half the width of each of the webs beforefolding. A stack, such as is illustrated in FIG. 8, is shown positionedin FIG. 11 within a carton 34 having an oval shaped perforation line 35in its top panel for the purpose of providing an opening in the toppanel when the perforation line is broken. Since the FIG. 8 stack isequal in width to onehalf the width of a tissue web prior to folding,the carton 34 may be only slightly greater in width than this dimension.

The conventional tissues now on the market which are individuallyremovable from a carton are ordinarily C- folded, as illustrated in FIG.10, each tissue comprising a lowear bottom fold k extending for thewidth of the stack and upper narrower folds k and k A carton 34a for theC-folded tissues is slightly larger than the stack of tissues in widthand is also commonly provided with an oval shaped perforation line 35awhich provides an Opening in the top panel for removal of the tissuesone at a time from the carton. A gap of about /2 inch is commonlyprovided between the inner cut edges of the folds k and it so as toallow a person reaching through the opening in the top panel to graspone or the other of the cut edges forming the ends of the folds k and kof the uppermost web segments. Dut to this gap between the folds k and kthe width of the stack of webs must be greater than onehalf the width ofa web in its unfolded condition; and, therefore, both the width of theC-folded stack of webs as well as the width of the carton for the stacksegments must be greater than the widths of the stack of web segmentsand carton, respectively, using the modified Z-fold, as will be notedfrom comparing FIG. 10 with FIG. 11. Thus, a carton for the modifiedZ-folded tissues may be less space consuming than a carton for theconventional C-folded tissues.

With respect to the modified Z-folded tissues as interfolded,illustrated in FIG. 9, the width of the stack also may be exactly equalto one-half the width of a web as contrasted to the C-folded tissues, astack of which has a width greater than one-half the web width.

The combination folding boards A B A ,B etc., which may be used toeither provide a modified Z-fold as illustrated in FIG. 8, or aconventional inter-fold as illustrated in FIG. 7, allow the machine tobe used for making either type of tissue stack with only a rethreadingof webs to make the change. In this connection, it may be desirable toutilize the FIG. 8 type of folding with relatively deep cartons, whileutilizing the FIG. 7 interfold ing with thinner cartons and simply byrethreading the same machine, either type of folding may be produced,and two separate machines are not necessary.

It is to be understood that the invention is not to be limited to thespecific constructions, arrangements and devices shown and described,except only insofar as the claims may be so limited, as it will :beunderstood to those skilled in the art that changes may be made withoutdeparting from the principles of the invention.

What is claimed is:

1. In a machine for folding uniform width webs of sheet material into astack of a width of one-half web width, a plurality of folding devicesdisposed in series and each adapted to fold a web drawn over the deviceand along an ultimate path of travel, each of said folding deviceshaving web guide means over which a longitudinal intermediate zone ofits respective web may be drawn along said path without being foldedover or under adjacent web zones and each said folding device includingfirst folding means across which a first web edge zone on one side ofsaid intermediate zone may be drawn and which folds the web zoneunderneath said intermediate web zone along a first fold line and eachsaid folding device also including second folding means across which asecond web edge zone on the other side of said intermediate zone may bedrawn for the purpose of overfolding said second edge zone over saidintermediate zone on a second fold line, said folding devices beingpositioned with respect to each other so that said first fold lineproduced by said folding devices are substantially on the longitudinalcenter of the respective webs folded by said devices and on oppositesides of said path for alternate ones of said folding devices in saidseries and the second fold lines for alternate ones of said foldingdevices in the series are disposed substantially one-fourth the width ofthe web from opposite edges of the respective webs folded by the devicesas the webs travel over said folding devices into said path so that themachine produces an elongate stack of folded webs in said path with eachweb being overfolded from substantially the longitudinal center of thestack to an edge of the stack.

2. In a machine as set forth in claim 1, said guide means of each saidfolding device including a first straight edge over which thelongitudinal intermediate zone passes and said first folding meansincluding a second folding edge having a point of intersection with saidfirst edge and extending along one edge of said path, a third foldingedge extending diagonally from said point to the other edge of said pathwith said three folding edges disposed in a common plane, and a fourthfolding edge extending at obtuse angles with respect to said first andsecond folding edges whereby the first web edge zone of the respectiveweb passes successively over said fourth, second and third folding edgesto be folded underneath said intermediate web zone.

3. In a machine as set forth in claim 2, said second folding means ofeach said folding device including a fifth folding edge disposed in acommon plane with said fourth folding edge and extending from a pointspaced from said first named point and at an obtuse angle with respectto said first folding edge and a sixth folding edge extending from saidsecond named point obliquely to said second folding edge whereby saidsecond edge zone of the respective web passes successively over saidfifth and sixth folding edges to be folded over said intermediate zone.

4. In a machine for folding a stack of webs of sheet material, aplurality of folding devices disposed in tandem and each adapted to folda web drawn over the device and along an ultimate path of travel, eachof said folding devices having a surface over which a longitudinalintermediate zone of its respective Web may be drawn along said pathwithout being folded over or under adjacent web zones, each said foldingdevice also having a plurality of folding edges across which a first webedge zone on one side of said intermediate zone may be drawn and whichfold the edge zone underneath said intermediate web zone, each saidfolding device also having a plurality of other folding edges acrosswhich a second web edge zone on the other side of said intermediate zonemay be drawn for the purpose of overfolding said second edge zone oversaid intermediate zone whereby to produce a stack of such folded webstraveling in said path, said surface of each of said folding devicesextending at an angle with respect to said ultimate path and having thecomplete Width of the web folded by the device passing over saidsurface, said plurality of other folding edges including an edge in saidsurface and an edge providing bar in said path and extending at an acuteangle across said path, said second edge zone passing sequentially oversaid first edge and over said bar so as to overfold said second edgezone over said intermediate zone.

5. In a machine for folding a stack of webs of sheet material, aplurality of folding devices disposed in tandem and each adapted to folda web drawn over the device and along an ultimate path of travel, eachof said folding devices having a surface over which a longitudinalintermediate zone of its respective web may be drawn along said pathwithout being folded over or under adjacent web zones, each said foldingdevice also having a plurality of folding edges across which a first webedge zone on one side of said intermediate zone may be drawn and whichfold the edge zone underneath said intermediate web zone, each saidfolding device also having a plurality of other folding edges acrosswhich a second web edge zone on the other side of said intermediate zonemay be drawn for the purpose of overfolding said second edge zone oversaid intermediate zone whereby to produce a stack of such folded webstraveling in said path, said surface of each of said folding devicesextending at an angle With respect to said ultimate path and having thecomplete width of the web folded by the device passing over saidsurface, said first named plurality of folding edges including a firstedge in said surface, a second edge extending in said ultimate path andat the edge of the said stack, and a third edge in said path andextending at an acute angle across said path, said first edge zonepassing over said first, second and third edges sequentially in order tofold said first edge zone underneath said intermediate web zone, saidplurality of other folding edges including a fourth edge in said surfaceand a fifth edge provided by a bar in said path and extending at anacute angle across said path, said second edge zone passing sequentiallyover said fourth and fifth edges so as to overfold said second edge zoneover said intermediate zone.

References Cited UNITED STATES PATENTS 10/1965 Presnell et al. 27040 12/1966 Couzens et al 27040

